The present disclosure relates to stented prosthetic heart valves having a paravalvular sealing wrap.
A human heart includes four heart valves that determine the pathway of blood flow through the heart: the mitral valve, the tricuspid valve, the aortic valve, and the pulmonary valve. The mitral and tricuspid valves are atrioventricular valves, which are between the atria and the ventricles, while the aortic and pulmonary valves are semilunar valves, which are in the arteries leaving the heart. Ideally, native leaflets of a heart valve move apart from each other when the valve is in an open position, and meet or “coapt” when the valve is in a closed position. Problems that may develop with valves include stenosis in which a valve does not open properly, and/or insufficiency or regurgitation in which a valve does not close properly. Stenosis and insufficiency may occur concomitantly in the same valve. The effects of valvular dysfunction vary, depending on the severity of the disease, and can have significant physiological consequences for the patient.
Recently, flexible prosthetic valves supported by stent structures that can be delivered percutaneously using a catheter-based delivery system have been developed for heart and venous valve replacement. These prosthetic valves may include either self-expanding or balloon-expandable stent structures with valve leaflets attached to the interior of the stent structure. The prosthetic valve can be reduced in diameter, by crimping onto a balloon catheter or by being contained within a sheath component of a delivery catheter, and advanced through the venous or arterial vasculature. Once the prosthetic valve is positioned at the treatment site, for instance within an incompetent native valve, the stent structure may be expanded to hold the prosthetic valve firmly in place. One example of a stented prosthetic valve is disclosed in U.S. Pat. No. 5,957,949 to Leonhardt et al. entitled “Percutaneous Placement Valve Stent.” Another example of a stented prosthetic valve for a percutaneous pulmonary valve replacement procedure is described in U.S. Patent Application Publication No. 2003/0199971 A1 and U.S. Patent Application Publication No. 2003/0199963 A1, both filed by Tower et al.
Although transcatheter delivery methods have provided safer and less invasive methods for replacing a defective native heart valve, leakage between the implanted prosthetic valve and the surrounding native tissue is a recurring problem. Leakage sometimes occurs due to the fact that minimally invasive and percutaneous replacement of cardiac valves typically does not involve actual physical removal of the diseased or injured heart valve. Rather, the replacement stented prosthetic valve is delivered in a compressed condition to the valve site, where it is expanded to its operational state within the native valve. Calcified or diseased native leaflets are forced open by the radial force of the stent frame of the prosthetic valve. These calcified leaflets may not completely conform to the stent frame, and any gaps between the stent frame and the native valve can be a source of paravalvular leakage (“PVL”). The closing pressure differential across the prosthetic valve can cause blood to leak through the gaps between the implanted prosthetic valve and the calcified anatomy. Such paravalvular leakage can be highly detrimental to the patient.
Because the aforementioned prosthetic valves are delivered via transcatheter procedures, there is an interest in reducing the profile of the compressed prosthetic valve during delivery while still providing a paravalvular leakage prevention wrap. The present disclosure addresses problems and limitations associated with the related art.